Automatic banjo mute



l April 9, 1929 w. J, DAvlDsoN Ax-:T Al. 1,708,169

AUTOMATIC BANJO .MUTE

Filed Aug. 2. 1926 2 Sheets-Sheet 1 @w/WMMW April'9, 1929. yv. J. DAvlDsoN ET AL n MI 1,703,169

' AUTOMATIC BANJO MUTE Filed 1m92.192s 2 Sheets-sheet 2 a# @WM atented Apr. 9, 192

"Unirse stares r'aAreNT oFFicE.

WILLAM JULIN DAVDSON AND MILTON G. W'QLF, GF CHICAGO, ND ADOLPH BERDICH, F RIVERSIDE, ILLINOS.

AUTOMATIC BANJo 'stern appneauon med august e, 192e. serial N. 126,408.

Our invention relates to muting devices for misical instruments in the nature of banjos and the like.

Since it is, at present, ditlieult to mute an instrun'ient while playing, as it necessitates the placing of the mute on the bridgeby the player who thus loses several bars of the music, one object of our invention is to provide an improved mute for dampening the vibrations of the diaphragm of a musical instrument, and also to provide such means that the player may operate the mute independently of his hands while the instrument is being played.

The secret of operation of the device which we have devised lies in the angle at which the instrument is disposed by the player, as will appear below, the muting mechanism being automatic and gravity-controlled.

A further object ofour invention -is the provision of a mute operating mechanism of relatively simple but durable and dependable construction, which is readily attached to vor detached from the musical instrument, without requiring any change in the construction of the instrument, and which is entirely withinthe body of the instrument, thus eliminating from view vall traces of the mechanism and in no way impairing the beauty or tone of the instrument,

An important feature of our invention is the composition of the mute which we use. After long' experiment with variousv metals and compositions, we have found that a mute constructed of lead is best suited to absorb the musical vibrations and to give outsofter and deeper tones. It is further to be noted that the lead mute, which, as will later be described in detail, slips into place in wedge.-l like fashion beneath the head and in'registration `with the bridge,the diaphragm being bef tween the mute and the bridge, is self-lubri eating due to the inherent slippery, oily chan acter of themetal itself. f

Further objects will become apparent from the following description and el aims, taken in connection with the accompanying drawingsY in which:

Figure l is a view looking at the inside of the shell toward the head of a banjo equipped with the'mute and gravity-controlled mechanism embodying our invention;

Fig. 2 isa substantially vertical sectionaf4 view of the circular body portion of a banjc.

mute and gravity-eontrolled mechanism em-` bodying our invention, the full-line showing the device in uniting position and the dotted line showing'the position of the weight and shaft when the device is not in vmating position;

Fig. 6 is a perspective view looking at the device from a diifercnt angle, and

Fig. 7 is a detail perspective view of the blocklwhich carries the inuting member and is carried by the gravity shaft'.

Referring to Fig. 2, an ordinary banjo con-l struction is shown with a rim l and a skin 2 which is stretched over a {iesh hoop 3, said hoop being retained in place vin the usual manner by a tension ring 4. A bridge 5 is shown, supporting the strings 6 which extend from the tail-piece 7 to the lneck which is indicated at Eef Fig. l'. i l

Again referring to Fig. 2, a resonator is shown at 9, supported on the underside of the rim by the clamp 10 which is fastened on the stick 17, said resonator being secured to said clampby thev serew'll.'lv The resonator, attached in this position,` opposes the diaL phragm Vor skin, but is spaced from the lower side of the rim by a substantial 'distance in order to provide an open resonating chamber.

rthe mechanism,,towhich the subject-matter our invention more particularly relates, will new be described. ln a general way, this mechanism comprises, as shown in Fig. 3, a mii-ting member 12, the stem22 of which is adjustably secured by the thumb screw 13 to a block o.; carrier 14.-, said block being secured to the shaft l5 which is, in turn, mounted in bearin 16, said bearings being secured upon the by the clamp 18 with which vthc :rings are integrally formed. Said clamp is secured to the stick by the thumb screws 23 and di weight 19 is adjustably secured to the saidL shaft by the screw 20. The axis ot said shaft is disposed neither in the axis the axis Qt the neck, but it is so disposed that any movement oit the instrun'ient, about the axis ot either the body or the neck, will throw the weight oil center, thus moving the device Ainto muting position. lt follows that the combination oi? a movement about the axis ot the body and a movement about the axis oit the neck will still more readily throw the weight ott center.

The angle ot the shalt may be changed to suit the player by means ot the screw 2l.

It will be noted, further, that the stein ot the uniting member is flattened on one side so as to prevent said member trom turningI in the block.

This muting member is preferably mane o t lead, since experiment has shown that metal best adapted to be used with this device, tor. not only is lead highly ductile, by which it is meant that it most readily absorbs musi-al vibrations, but also as it is sollt-lubricating due to its oily surface, it slides easily i i wedge-like position in contact with the sain under the bridge. This self-lubricating quality ot the lead is oi' importance, tor, since it is necessary that the muting member be brought snugly under the bridge, the device so operates that when the weight iialls oiil center, setting in motion the sha't't and bloei; att-ached thereto, the muting member is moved in an arcuate direction into contact with the skin, along the su "la oit which it moves, the pressure ot said member against said skin increasing the tarther the Yi'ormc.I is moved, Vuntil it is iinallywedged up tightly under the bridge. Obviously, the oily charactor ot the lead allows the muting meniiber to slidealong in Contact with the skin without doineV the latter any harm, and as it overcomes friction, without apirireciably reta rdi ng the movement thercoii while it is being 'forced into muting relation with the skin and bridge.

By uniting relation is meant that position in which the muting member must be in relation to the skin and bridge to obtain the muted eiieet when the instrument played. This position is obtained when the muting member is held in contact with the skin, and imn'iediately under and registeri with the bridge.

To describe the operation et our device more specifically, we shall new reter to lig. 5. The dotted lines indicate the position oi the weight 19 and shaft l5 when the instrument is held in normal position, the mutiny; member 12 being, when the instrument so held, disengaged and held away trom the skin and bridge. Now, when the neel: o'lf the instrument, which is in the direction o' o, is raised, or when the instrument is rotated in the direction ot the arrow (Z, or when the instrument is given a slight tilt combining these two inoven'ients, the weight 1.9 italls oil center and nieves, by th" torce ot gravity, to the position shown in 'tull li es at l). its the w *ight moves io this new posit-ion, it causes tl e shalt l5 to rotaie in the bearings lil, and this rotation, in turn, causes he block il lo rotate in the direction oit the arrow c. rthe uniting member ljeing secured to he blot-iir ifi, is moved, by the rotating .uoveuunt ol said block, in an arcuate direction until it comes in contact with the skin. 'The clamp it which secures the bearings lo is so oosiiwfrml upon the stiel; l hat the uniting iembcr, after movin` the above mcuinneil arcuate direction, is slid along the shin, con ing in ever tighter contact as the movement continues, and comes to rest, wed ed in contact with the shin and in regisiraiion witl bridge, causing many oi? the vilnfations comthrough the bridge to be absorbed by the mating member, thus cutting down he brations emanating from the head oif the in strument.

lhen the instrument is moved or tilted in directions the reverse o'i those above described, the weight 19 'tails back into the dotted-line position, causing' the shaft. to rotate in a direction the reverse ot the above described, which, in turn, causes the uniting member to leave its wedged position and to break its contact with the skin, thus bringing back to its disengaged position and allow .ii g the vibrations emanate forth trom the head in their :full volume.

ln Fig. 7 it will be noted that the block l-l, which is carried on the shalt l5, s slotted, as

i shown in 25, so that the said Vdia may he easily and securely mount-ed the-ein against rotation by Vturning down the thumb screw 2G.

lt will thus be seen that our inngrovcd mut ing device may be prickly and conveniently attached to any instrument having a vibratory head, such, tor instance, a banjo, without changing any ot the parts or niulilating the instrument, and without any part ot the device being exposed to view.

it will also be readily seen that the grav ik., Lin..

it f control oi the muting member will permit o t the instrument being muted by a slight rotation ot the body, or a tilting ot the same, which movements will in time be performed subconsciously by the player when it is dew sircd to produce `so-ltaud muted tones.

`While we have shown and described a pre- 'terred embodiment ot our invention, it will be understood that the details et construction are capable oft wide modiiication and variation, while stili retainingl the itunda 1nental principles thercoii. Ence, we rcffierve all such modifications, variations and mechanical equivalents as Afall within tl e spirit and purview ot the appended claims.

lVe claim:

l. in combination with a stringed musical direction to Wedge the same finto muting relation with respect `to rthe rsaid head and bridge, and yinea-ns for `securing the muting lmember rand gravity-eontrolied Wei gli-t Within the body of the instrument.

ll. In combination witha stringed musical instrument having a bridge and a. vibratory head, an adjustable muting member, gravitycontrolled means for inovi-ngs'aid member in an arcuate direction to Wedge the same into muting relation with respect to said head and bridge, and means for securing` the muting member and gravity-controlled Weight within the body of the instrument.

In combination witha stringed musical instrument having a bridgeand a vibratory head, a muting member, adjustable gravitycontrolled means for moving said member in an arcuate direction to Wedge the same into muting relation With said head and bridge, and means for securng the muting member and gravity-controlled Weight Within the body of the instrument; y

G. In combination with a stringed musical instrument having a bridgev and a vibratory head, an adjustable muting member, adjustable gravity-controlledv means for moving said member in an arcuate direction to Wedge the saine into mating relation with said head and bridge, and means Vfor securing the mut-l ing member and gravity-controlled Weight within the body of the instrument. I

7. In combination Witlia stringed musical instrument having a bridge and a vibratory head, a mating member, gravity-controlled means for moving said member in an arcuate direction to Wedge the same-into muting relation with said bridgeand head, and adjustable means for securng the muting member Cfl and gravity-controlled Weight Within the body of the instrument. I

8. In combination with a stringed musical instrument having a bridge and a vvibrator-y head, an adjustable muting member, gravitycontrolled ineans'i'or'moving said member in an arcuate direction to Wedge'the same. into muting relation With said bridge and head, and adjustable means for, securing the muting member and gravity-eontrolled Weight Within the body of the instrument.

9. In combination With a stringed musical instrument havinga bridge and a vibratory head, a mating member, adjustablev gravity- `controllecil means for :movi-ng said member `in an arcuate direction Ato lWedge the saine into mating relation with said bridge and fliead, and adjustable means for securing the mut-ing member and gravity-controlled weight Within the body oi the instrument.

10. In `cenibination with a stringeiil musica'l instrument having a. bridge and a vibra- Itory head, a inutiiig member adjustable 4with respect `to the vibratory head, adjustable gravity-eontrolled means 'for moving said member in an arcuate direction to wedge lthe saine -into muting relation with said bridge and head, and adjustable means ttor securing th-e inutino member and gravity-controlled mea-ns Within the body of the instrument.

n ll. A iniiting device for stringed -innsical instruments Which have a bridge and a vibra- 4tory head, comprising a uniting member-rand' gravity-controlled means for moving sait'l member i-n an arcuate direction to we( ge the same into muting relation with the said head and bridge.

l2. A muting device 'tor stringed musical instruments which have a bridge and a vibratory head, comprising a muting member, gravity-controlled means for moving said member in an arcuate direction to wedge the same into iiiuting relation with the said head and bridge, and means for securing the device Within the body of the instrument.

13. A muting device tor stringed musical instruments which have a bridge and a vibratory head, comprising a uniting' member and means acting automatically upon the shifting of the position of the'instrunient to move the said member into registration vwith the said bridge and into Contact with said head tor muting the vibrations thereof. y

14C. A muting device for stringed musical instruments which have a bridge and a vibratory head, comprising a muting member, clamping means, and means acting automatically upon tlie shifting ot the position of the instrument to move said member into contact with said head and into registration with said bridge. y

l5. A muting device for stringed musical instruments Which have bridge and a vibratory head, comprising an adjustable muting member, clamping means, and lmeans acting automatically upon the shitting of the position of the instrument to move said member into contact With said head and into registration with said bridge.

16. A muting device 'for stringed musical instruments which have a bridge and a vibratory head, comprising a mating men'iber,

vclamping means, and gravity-controlled means 'for moving said member into registration With said bridge and into contact with ksaid head for muting the vibrations thereof.

I7. A muting device for stringed musical instruments which have a bridge and a vibratory head, comprising an adjustable muting Cil member, :i gravity-centro]led adjustable means se r vi n g to bring said member' into mntrelntion with said bridge and head, und means lor udjnstably clamping the mute to the instrument.

i8. A mnting` device for stringed musical instruments which have e bridge und :i vibratorv head7 eenipiisirigY :ni adjustable mnt-ing member :1. gravitjr-controlled adjustable weight 'for moving' smid member inte registration with said bridge and into contact with said head :md means ttor a-djlistsibly clamping the mute te the stick of the .instrument in such nmnner that the device is entireiy contained within the body et the instrument.'

19. A mnting; device for stringed musical instruments .vhieh have ai bridge und a vibratory head, having in Combination, a mnting n'rembe clmnpingg' means, and gravity-controlled means :for operating seid mute, said hinting member Composed of material suited to absorb n'nisienl vibrations and mezms for moving .sa-id member into register with said bridge and in to contact with said heard; Suid elzimping means serving te secure the device Within the body of the instrmnent, md smid Qravity-contro]led men s compre-ring zin udjnstzible weight on u shzrt connected io the seid member, said shzilt being; se positioned that the weight will lull oil center on certain movements of said ilistrmnent.

20. L hinting device for stringed musical instruments which have n bridge :i nd :1 vibrartery heed7 comprisili;Y a member composed el :i duetile material capable et nbsorbinfrV musieiil vibrations, :md e gruvity-controled means for bringing said member into registration with the said bridge and inte Contact with seid head 'for mntiiii;` the vibrations thereof.

In Witness whereof, we have hereunto subscribed our names. 

